Explanation

Question 1. Option D is correct. From 1997 to 1999, Airline A bought 44% of its 250 airplanes, or 110 airplanes. In the same time period, Airline B bought 26% of its 450 airplanes, or 117 airplanes. The sum of 110 and 117 is 227 airplanes, choice (D).

Question 2. Option D is correct. Looking at the 2002 inventory at Airline A, 4% was purchased in 1994. The actual number in inventory is 4% of 250, or 10 airplanes. Of the 25 airplanes purchased, 15 must have been sold. Use percent translation to translate the question into algebra: “15 is what percent of 25” becomes 15= \(\frac{x}{100}*25\). Solving for x gives you 60, choice (D).

Question 3. Option C is correct. Although Airline A has fewer airplanes than does Airline B, you have no information about each airline’s customers; choice (A) is incorrect. While the percent of airplanes purchased by Airline B is twice as large as that purchased by Airline A, the actual number of airplanes purchased by Airline B is approximately four times as large as those for Airline A, not twice as large. So, choice (B) is incorrect. To evaluate choice (C), you need to add the percents in each column year by year until you get to 50%. The airplane with the median age for Airline A was
purchased in 1997. For Airline B, the median is between 1995 and 1996, making the median age for the airplanes in Airline B’s inventory older. This validates choice (C), the only correct answer.